Conventional set wrenches include an elongated handle which terminates in an adjustable wrench head having a fixed jaw and an adjustable jaw. The adjustable jaw is selectively movable with respect to the fixed jaw to vary the spacing between the jaws depending on the size or width of a nut or bolt head which is engaged by the wrench for loosening and tightening. However, while they typically have gross adjusting capability, conventional set wrenches typically cannot be precisely adjusted to a particular width depending on the size or width of the nut or bolt which is to be tightened or loosened. Thus, slippage of the wrench with respect to the nut or bolt may occur, resulting in stripping of the nut or bolt over time.